Fuel injection pumping apparatus

ABSTRACT

A fuel pumping apparatus for an internal combustion engine, includes a control rod movable towards a minimum fuel position by means of a governor mechanism, which is responsive to the speed of an associated engine, the governor mechanism acting against the action of a governor spring. The mechanism includes an operator controlled member, which is movable to increase the force exerted by the spring, and in addition can effect stressing of a resilient means against the action of which the control rod must be moved by the governor mechanism as the speed of the engine increases.

United States Patent 1191 Tomsett Sept. 2, 1975 54] FUEL INJECTIONPUMPING APPARATUS 3,659,570 5 1972 Yoshino 123/140 R 3,714,935 2/1973Dreisin 123/140 R [75] Inventor: Derek Wallace melt, waltham 3,759,2369/1973 Staudt 123/140 R Cross, England [73] Assignee: Simms Motor UnitsLimited,

London, England [22] Filed: Mar. 2, 1973 [21] App]. No.: 337,398

Primary ExaminerChar1es .1. Myhre Assistant Examiner-David D. ReynoldsAttorney, Agent, or Firml-lol1rnan & Stern 1 1 ABSTRAET A fuel pumpingapparatus for an internal combustion engine, includes a control rodmovable towards a minimum fuel position by means of a governormechanism, which is responsive to the speed of an associated engine, thegovernor mechanism acting against the action of a governor spring. Themechanism includes an operator controlled member, which is movable toincrease the force exerted by the spring, and in addition can effectstressing of a resilient means against the action of which the controlrod must be moved by the governor mechanism as the speed of the engineincreases.

4 Claims, 2 Drawing Figures PATENTEDSEP 21% FIG.

FIG. I

FUEL WJECTION PUB WING APPARATUS FIELD OF THE INVENTION This inventionrelates to liquid fuel injection pumping apparatus for supplying fuel tointernal combustion engines.

BACKGROUND OF THE INVENTION The apparatus is of the kind comprising aninjection pump having an adjustable control member movable to effectcontrol of the amount of fuel delivered by the apparatus at eachinjection stroke, the apparatus also in eluding a governor mechanismcomprising centrifugally operable weights movable with increasing speedin opposition to the action of a governor spring, a lever connecting thegovernor mechanism with the control member whereby as the weights movein opposition to the action of the spring the control member will bemoved to reduce the amount of fuel supplied by the apparatus at eachinjection stroke, an operator controlled member for controlling theforce exerted by the spring and a stop for limiting the movement of thecontrol member in one direction thereby to limit the maximum amount offuel which can be delivered by the apparatus at each injection stroke.

SUMMARY OF THE INVENTION The object of the invention is to provide suchan apparatus in a simple and convenient form.

According to the invention in an apparatus of the kind specified thereis provided an adjustable member positioned so that control member canengage therewith, and resilient means connecting said adjustable memberwith said operator controlled member whereby" upon movement of saidoperator controlled member to increase the fuel supplied by theapparatus at each injection stroke, the adjustable member will be movedso that during movement of the control member to increase the speed ofthe engine, the control member will be operative to move the adjustablemember and said resilient means will be stressed.

One example of a liquid fuel pumping apparatus in accordance with theinvention will now be described with reference to the accompanyingdrawing in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I shows part of a liquid fuelpumping apparatus in vertical section, with portions being showndiagramatically; and

FIG. 2 is a transverse section taken substantially on the plane of line22 of FIG. 1, with portions removed for purposes of clarity.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring to the drawing there isprovided a hollow housing which is adapted to be mounted upon a pump 9.The pump 9 is of conventional design and includes an injection pumpoperable in timed relationship with an engine with which the apparatusis associated and the pump is driven by a shaft 11 which is coupled tothe engine. The shaft 11 in fact is extended through the housing 11 anda closure member for the housing is provided which supports a bearingfor the shaft. The projecting portion of the shaft is coupled by meansof a coupling (not shown) to the engine.

The injection pump includes an axially movable control member in theform ofa rod 12, the rod 12 also extending into the housing 10. Theaxial position of the rod 12 determines the quantity of fuel deliveredat each injection stroke of the injection pump and it is arranged thatmovement of the rod towards the right as shown in the drawing effects anincrease in the quantity of fuel supplied at each injection stroke.

The shaft ll mounts a governor weight assembly 13 and this comprises aplurality of eentrifugally operable weights which as the shaft rotates,move outwardly under the action of centrifugal force. The outwardmovement of the weights effects axial movement of a member which isshown diagrammatically at 14 and this member is coupled by means of alever also shown diagrammatically at 15 to the control rod 12. The lever15 is pivoted within the housing 10. For opposing the action of theweights, there is provided an elongated leaf spring which is showndiagrammatically at 16. The leaf spring bears at one end upon the memberindicated by the line 14 and at its other end it is pivotally con nectedto the housing. For stressing the spring, a roller 17 is provided andthis is movable by means of a pivotal, operator-controlled member 18against a ramp 19. It will .be seen that as the operator controlledmember 18 is moved in the clockwise direction, the roller 17 will movedownwardly and the effect of the ramp 19 will be to stress the spring 16so that an increased force is provided to resist the' outward movementof the governor weights under the action of centrifugal force.

The mechanism so far described constitutes a simple governor for thefuel pump and for a given setting of the operator controlled memberthere will be a eorresponding engine speed and the effect of thegovernor is that should the speed increase for any reason, then theweights will move outwardly against the action of the spring 16 and theeffect of this is to move the control member 12 towards the left therebyto reduce the amount of fuel supplied at each injection stroke by thepump 9 to the engine. Conversely, if the engine speed should fall thenthe weights will move inwardly and the effect will be that the controlrod 12 will be moved towards the right thereby to increase the quantityof fuel supplied to the engine.

The operator controlled member 18 is mounted upon a shaft 20 extendingtransversely within the housing and connected externally of theapparatus to a control lever or control pedal.

Mounted on the control rod 12 is an abutment 21 and this is shaped forco-operation with a pair of lever members 22, 23. Lever 23 is mounted ona shaft which extends exterior of the housing and can be moved to engagethe abutment 21 to effect movement of the control member 12 towards theleft and to a position in which no fuel is supplied by the apparatus.The lever member 23 therefore constitutes the stop control of theapparatus.

The lever member 22 is pivotally mounted about a shaft and is extendedto form a mounting for an adjust ing screw 24 in addition, the :mainportion of the lever member 22 acts between the abutment 21 and an adjustable stop 25 to control the maximum movement of the control rod 12towards the right and thereby determines the maximum amount of fuelwhich can be supplied at each injection stroke. The adjusting screw 24bears upon a ledge which is formed on a further lever 26 which isangularly movable about the axis of movement of the lever member 22..The lever 26 has an extended portion which at its lower end is inclinedtowards the axis of the shaft and mounted upon the extended portion is aleaf spring 27. The leaf spring 27 bears against a surface 28 formed onthe boss which mounts the operator controlled member 18 upon the shaft20.

As shown in the drawing, the operator controlled member 18 is in theidling position, but as it is moved by the operator to effect anincrease in the speed of operation of the engine, the surface 28 willurge the end of the spring with which it abuts, in a direction generallyclockwise about the axis of movement of the lever 22. Movement of thelever 26 will, through the intermediary of the adjusting screw 24,effect clockwise movement of the lever 22.

It will be appreciated that the position of the various parts shown inthe drawing is with the engine at rest and the operator controlledmember 18 in the idling position. When the engine is started, thecontrol rod 12 will be moved towards the left by the action of thegovernor weights. As the operator controlled member 18 is moved toincrease the amount of fuel, the normal governing action will takeplace, but in addition, the lever 22 will be moved in the clock-wisedirection so that during movement of the control rod towards the rightthe abutment 21 will contact the lever 22 before it reaches the maximumfuel position. The effect of this is that the spring 27 will be stressedas the control rod 12 moves towards the maximum position. Thus thespring 27 acts in opposition to the main governor spring 16. Control rod12, abutment 21, and lever 22 are shown in the at rest position in FIG.1, but also assume the same position when the apparatus is in themaximum fuel position when the engine is running.

'The fact that the spring 27 is stressed is particularly useful in theevent that a sudden increase in load be applied to the associated engineand no adjustment is made of the driver operable member 18. Such anexample arises in the case of a tractor which is drawing a plough andwhich has a manual throttle. If the plough should strike a tree root andthe load suddenly increase, without movement of the throttle to increasethe amount of fuel supplied, the tractor speed would decrease quickly.In the present case, however, the decrease in speed will be minimiseddue to the excess governor spring force deflecting spring 27 andallowing the lever member 22 to move to a higher fueling level until itcontacts adjustable stop 25. The profile against which spring 27 bearson the pivotal operator controlled member 28 is such that for any givenassociated engine speed the maximum fuel that can be obtained is notdependant on the position of the operator controlled member.

I claim:

1. A liquid fuel injection pumping apparatus comprising an injectionpump, an adjustable control member movable to effect control of theamount of fuel delivered by the pump at each injection stroke, agovernor mechanism for controlling the setting of said control member,said governor mechanism comprising a centrifugally operable weight and agovernor spring, the weight acting with increasing speed to move thecontrol member against the action of the governor spring to reduce theamount of fuel supplied by the pump, an operator controlled member foradjusting the force exerted by the governor spring, an adjustable memberpositioned so that the control member can engage therewith and resilientmeans connecting said adjustable member with said operator controlledmember whereby upon movement of said operator controlled member toincrease the fuel supplied by the pump at each injection stroke, theadjustable member will be moved so that during movement of the controlmember to increase the fuel supplied by the pump, the control memberwill 'contact the adjustable member and said resilient means will bestressed.

2. An apparatus according to claim 1 including a stop engageable withsaid adjustable member for limiting the maximum amount of fuel which canbe supplied by the injection pump.

3. An apparatus as claimed in claim 2 in which said resilient means ismounted upon a lever member, said lever member and said adjustablemember having ad- 40 justable abutment means disposed therebetween.

4. An apparatus as claimed in claim 3 in which said

1. A liquid fuel injection pumping apparatus comprising an injectionpump, an adjustable control member movable to effect control of theamount of fuel delivered by the pump at each injection stroke, agovernor mechanism for controlling the setting of said control member,said governor mechanism comprising a centrifugally operable weight and agovernor spring, the weight acting with increasing speed to move thecontrol member against the action of the governor spring to reduce theamount of fuel supplied by the pump, an operator controlled member foradjusting the force exerted by the governor spring, an adjustable memberpositioned so that the control member can engage therewith and resilientmeans connecting said adjustable member with said operator controlledmember whereby upon movement of said operator controlled member toincrease the fuel supplied by the pump at each injection stroke, theadjustable member will be moved so that during movement of the controlmember to increase the fuel supplied by the pump, the control memberwill contact the adjustable member and said resilient means will bestressed.
 2. An apparatus according to claim 1 including a stopengageable with said adjustable member for limiting the maximum amountof fuel which can be supplied by the injection pump.
 3. An apparatus asclaimed in claim 2 in which said resilient means is mounted upon a levermember, said lever member and said adjustable member having adjustableabutment means disposed therebetween.
 4. An apparatus as claimed inclaim 3 in which said resilient means comprises a leaf spring.